Macrosemimimus fegerti Schröder et al., 2012

Taxonomy

Kingdom: Animalia
Phylum: Chordata
Class: Actinopteri Cope 1871
Order: Semionotiformes Arambourg & Bertin 1958
Family: Callipurbeckiidae López-Arbarello 2012
Genus: Macrosemimimus
Species: Macrosemimimus fegerti
Author Citation Schröder et al., 2012

Geological Time Scale

Eon: Phanerozoic
Era: Mesozoic
Period: Jurassic
Sub Period: None
Epoch: Late
International Age: Tithonian (early)

Stratigraphy

Weissjura Group
Altmühltal Formation

Biostratigraphy

Hybonoticeras hybonotum Zone
Lithacoceras riedense Subzone
Lithacoceras eigeltingense beta Horizon

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 20 cm

Location

Steinbruch Ettling
Landkreis Eichstätt
Bavaria
Germany

• ettling
• jurassic
• macrosemimimus
• tff-oilshale-ch1264
• tithonian

Comments

Since the summer of 2007, the Jura Museum Eichstätt has maintained a scientific research excavation in the Ettling limestone quarry (Markt Pförring). For a long time, this limestone quarry was considered almost fossil-empty, until private collectors discovered a number of exceptionally well-preserved specimens. The Ettlingen site yielded numerous species previously unknown in the rest of the Plattenkalk region. The fish are very difficult to prepare - the preparation is done under the microscope purely mechanically by scraping only with fine needles and scalpels. 

The last two pictures are taken under UV light.
Recently Macrosemimimus was also found in the somewhat older lithographic limestones of Painten (Upper Kimmeridgian).
Taxonomy from Schröder et al. 2012.
Differential Diagnosis from Schröder et al. 2012, p. 513: "Medium-sized Macrosemimimus of up to ca. 20 cm standard length (SL), differing from the other species of this genus in the following combination of morphological features: skull bones smooth, devoid of ganoine; scales smooth and with straight posterior border except for a variably developed single posteroventral spine; small extrascapular bones placed lateral to posterior portion of parietals; preoperculum shallow leaving a naked area below the dermopterotic; maxilla with long articular process; moderately tritoral dentition; short longitudinal ridge on ceratohyal.

Line drawing of the head from Schröder et al. 2012, p. 516 (scale bar equal 1 cm)

 

References:

Schröder, K. M.; López-Arbarello, A.; Ebert, M. (2012). "Macrosemimimus, gen. nov. (Actinopterygii, Semionotiformes), from the Late Jurassic of Germany, England, and France". Journal of Vertebrate Paleontology. 32 (3): 512–529. doi:10.1080/02724634.2012.649626.

Ebert, M. & Kölbl-Ebert, M. (2014) Forschungsgrabung Ettling: Grabungsbericht 2014. Archaeopteryx 32:44-49